This patent application claims priority of EP patent application No. 00 104 234.0 filed Mar. 1, 2000, the content of which is incorporated herein by reference.
EOP-B 250 470 describes a robot for handling products in a three-dimensional space. Three arms are pivotably attached to a base. The three pivoting axes of the arms are arranged in a common plane and form a regular triangle. At the free end of each arm of a parallelogram linkage is affixed which other end is connected to a common carrier. The carrier carries in its center a gripper for handling the products. The gripper is joined by a telescopic bar with a servo motor for turning it. The upper joint of that connection is below the axes plane.
The problem which the present invention solves is to increase the volume of space which can be reached by the gripper relative to the length of the arms or conversely to reduce the arm length for the same volume covered. This problem is solved by the invention in which, briefly stated, a robot for handling products in a three-dimensional space is described. The robot comprises a base on which three arms are pivotably supported to pivote around three pivote axes arranged in a common axes plane. The three axes form a triangle with three corners. Each arm is mounted on a shaft. Each shaft is connected to a driving unit, e.g. a pneumatic or electric motor with or without a gear unit. All driving units are connected to a controller. Three connecting linkages connect the free ends of the arms to a carrier which is movable in space in all three linear dimensions and prevented from rotation around all three rotative dimensions. A telescopic fourth linkage connects a gripper rotatably supported on the carrier by two joints with a fourth driving unit fixed to the base. In the axes plane the base has an opening through which the fourth linkage extends. The upper joint of the fourth linkage is significally above the axis plane and on an opposite side of the axes plane than the carrier. No collision between the telescopic linkage and the other linkages can occur within the operating range.
By this measure the range that can be covered by the gripper can be substantially increased for a given arm length or the arm length can be reduced for a given range. This way eather the range or the speed of the robot or both can be increased. Speed is a critical problem with handling robots because it is crucial to the production capacity of a manufacturing or packaging line in which the robot is used.